phoenix-firestorm/indra/llcommon/llfasttimer.h

167 lines
4.4 KiB
C

/**
* @file llfasttimer.h
* @brief Inline implementations of fast timers.
*
* $LicenseInfo:firstyear=2004&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_FASTTIMER_H
#define LL_FASTTIMER_H
// pull in the actual class definition
#include "llfasttimer_class.h"
//
// Important note: These implementations must be FAST!
//
#if LL_WINDOWS
//
// Windows implementation of CPU clock
//
//
// NOTE: put back in when we aren't using platform sdk anymore
//
// because MS has different signatures for these functions in winnt.h
// need to rename them to avoid conflicts
//#define _interlockedbittestandset _renamed_interlockedbittestandset
//#define _interlockedbittestandreset _renamed_interlockedbittestandreset
//#include <intrin.h>
//#undef _interlockedbittestandset
//#undef _interlockedbittestandreset
//inline U32 LLFastTimer::getCPUClockCount32()
//{
// U64 time_stamp = __rdtsc();
// return (U32)(time_stamp >> 8);
//}
//
//// return full timer value, *not* shifted by 8 bits
//inline U64 LLFastTimer::getCPUClockCount64()
//{
// return __rdtsc();
//}
// shift off lower 8 bits for lower resolution but longer term timing
// on 1Ghz machine, a 32-bit word will hold ~1000 seconds of timing
inline U32 LLFastTimer::getCPUClockCount32()
{
U32 ret_val;
__asm
{
_emit 0x0f
_emit 0x31
shr eax,8
shl edx,24
or eax, edx
mov dword ptr [ret_val], eax
}
return ret_val;
}
// return full timer value, *not* shifted by 8 bits
inline U64 LLFastTimer::getCPUClockCount64()
{
U64 ret_val;
__asm
{
_emit 0x0f
_emit 0x31
mov eax,eax
mov edx,edx
mov dword ptr [ret_val+4], edx
mov dword ptr [ret_val], eax
}
return ret_val;
}
#endif
#if (LL_LINUX || LL_SOLARIS) && !(defined(__i386__) || defined(__amd64__))
//
// Linux and Solaris implementation of CPU clock - non-x86.
// This is accurate but SLOW! Only use out of desperation.
//
// Try to use the MONOTONIC clock if available, this is a constant time counter
// with nanosecond resolution (but not necessarily accuracy) and attempts are
// made to synchronize this value between cores at kernel start. It should not
// be affected by CPU frequency. If not available use the REALTIME clock, but
// this may be affected by NTP adjustments or other user activity affecting
// the system time.
inline U64 LLFastTimer::getCPUClockCount64()
{
struct timespec tp;
#ifdef CLOCK_MONOTONIC // MONOTONIC supported at build-time?
if (-1 == clock_gettime(CLOCK_MONOTONIC,&tp)) // if MONOTONIC isn't supported at runtime then ouch, try REALTIME
#endif
clock_gettime(CLOCK_REALTIME,&tp);
return (tp.tv_sec*LLFastTimer::sClockResolution)+tp.tv_nsec;
}
inline U32 LLFastTimer::getCPUClockCount32()
{
return (U32)(LLFastTimer::getCPUClockCount64() >> 8);
}
#endif // (LL_LINUX || LL_SOLARIS) && !(defined(__i386__) || defined(__amd64__))
#if (LL_LINUX || LL_SOLARIS || LL_DARWIN) && (defined(__i386__) || defined(__amd64__))
//
// Mac+Linux+Solaris FAST x86 implementation of CPU clock
inline U32 LLFastTimer::getCPUClockCount32()
{
U64 x;
__asm__ volatile (".byte 0x0f, 0x31": "=A"(x));
return (U32)(x >> 8);
}
inline U64 LLFastTimer::getCPUClockCount64()
{
U64 x;
__asm__ volatile (".byte 0x0f, 0x31": "=A"(x));
return x;
}
#endif
#if ( LL_DARWIN && !(defined(__i386__) || defined(__amd64__)))
//
// Mac PPC (deprecated) implementation of CPU clock
//
// Just use gettimeofday implementation for now
inline U32 LLFastTimer::getCPUClockCount32()
{
return (U32)(get_clock_count()>>8);
}
inline U64 LLFastTimer::getCPUClockCount64()
{
return get_clock_count();
}
#endif
#endif // LL_LLFASTTIMER_H